The Moller M400 Skycar uses Rotapower® rotary engines. Specifically, it is equipped with eight such rotary engines, arranged in four thrust-vectoring nacelles (each nacelle contains two counter-rotating engines). These engines are known for their high power-to-weight ratio and efficiency. The total power output of these engines is about 720 horsepower, and they can run on gasoline, ethanol, or methanol.
References:
Images: